html5-img
1 / 25

Highwall Stability Due to Ground Vibrations from Blasting

Highwall Stability Due to Ground Vibrations from Blasting. Dr. Kyle A. Perry Dr. Kot F. Unrug Kevin Harris Michael Raffaldi. PURPOSE. Objective : Study the effect of blast vibrations on the stability of highwalls and web and barrier pillars Methods Numerical Modeling Field Testing

sally
Download Presentation

Highwall Stability Due to Ground Vibrations from Blasting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Highwall Stability Due to Ground Vibrations from Blasting Dr. Kyle A. Perry Dr. Kot F. Unrug Kevin Harris Michael Raffaldi

  2. PURPOSE Objective: Study the effect of blast vibrations on the stability of highwalls and web and barrier pillars Methods • Numerical Modeling • Field Testing • Laser Scanning • Vibrations Monitoring

  3. PROGRESS • SASW Testing • Numerical Modeling • FLAC3D – Web and Barrier Pillars • Stress Distribution • Pillar Stability • 3DEC – Highwall Modeling • Laser Scanning • Displacement/Velocity • Field Data Collection

  4. SASW Testing • Dynamic Material Properties • Shear Modulus • Damping Ratio • Modulus/Damping Reduction Curves • Dynamic Model Calibration • Iterative Numerical Process

  5. SASW Testing

  6. Numerical Modeling Sub-Objective 1: Evaluate the influence of highwall mining progression on web/barrier pillar stability using FLAC3D Methodology • Simplification – 2D Section • Validation – Mark-Bieniawski • 5 Case Studies

  7. Material Properties Coal Material Model • Strain Softening Mohr-Coulomb Roof/Floor Interface • Bi-linear Mohr-Coulomb

  8. Material Properties Rock Material Model • Ubiquitous Joint Model with Softening

  9. Model Validation

  10. Model Validation

  11. Model Validation • Material Properties • Peak Strength • Calibration Reasonable • Web/Barrier Pillars • “Infinite Length” Assumption • 2D Cross Section • Plane Strain Validation

  12. Case Study Results

  13. Mining Progression Results

  14. Important Findings • Tributary Area Loading • Common Assumption • Arching Effect – Geology Dependent • Importance of Barrier Pillar Design • Mining Progression • De-stressing near Barriers • Asymmetric Loading • Probability of Pillar Failure/Highwall Collapse • Dynamic Impact on Web/Barrier Pillars

  15. Numerical Modeling Sub-Objective 2: Correlate active highwall sites with 3DEC for validation and additional testing Methodology • Routine trips collect scan data • Digitize geometry for mesh generation within 3DEC

  16. Primary Mine Site Pine Branch Mine • Perry County, KY • Mountaintop/Contour • Hazard 7 – Hazard 10 seams • 200’ – 300’ Highwall • Massive Sandstone Important Mine Data • Corehole Data • Mapping

  17. Primary Mine Site

  18. VIBRATION AND SCAN DATA Laser Scanning • Pre/Post Blast Capture • Mesh Generation for 3DEC • Geologic Data • 2 Primary Joint Sets • 85 Degree Dip • 110, 185 Direction Seismograph Deployment • Highwall Peak and Bottom • Single Event Vibration Data

  19. SUMMARY HIGHWALL STABILITY STUDY MODELING FIELD DATA DESIGN LIDAR VIBRATION RECORDS CALIBRATION BLAST AND DAMAGE CORRELATION FIELD TESTING LITERATURE/ EMPIRICAL COMPLETED MODEL NUMERICAL STUDY DRAW CONCLUSIONS

  20. Project Direction FLAC3D Modeling • Probability of Pillar Failure/Highwall Collapse • Dynamic Impact on Web/Barrier Pillars 3DEC Modeling • Solidify Static Model • Quantify/Correlate Damage and Vibrations • Sensitivity Studies • Ratio of PPV • Geology • Highwall Geometry

  21. QUESTIONS?

More Related